12
Appendix 2
Fine Azimuth Adjustment
This can be done using an oscilloscope and a test record or by using good records in a good
system and listening to the sound. Cartridges with fine profiles (VDH, Microline etc.) are
more sensitive to this adjustment. On the other hand cheaper cartridges are not made so well,
making fine adjustment more useful.
With an oscilloscope we measure the differences in crosstalk between both channel. The idea
is that on both channels this is equally small. For that we need a test record with tracks
recorded for left and right channels separately. Then we compare crosstalk from the left
channel on the right channel- which is a very small signal, to the same type of signal from the
other channel. By adjusting azimuth, crosstalk on both channels should be made equal.
Listening from LP:
Start listening with the tube in zero position, with the marking lines aligned. Listen to the
sound-stage, the focus and the stability of the instruments. Release the two locking screws
and rotate the Allen key so that tube rotates for approximately the width of the mark. Listen
and then rotate tube for a similar amount in the opposite direction and again listen. Adjust the
arm to the position in which the best sound was obtained. In this position make further
adjustments by turning the Allen key for a quarter turn in one direction, listening and then
turning a quarter turn in the other direction and listening.
Continue this process making ever decreasing adjustments, 1/8 of a turn, then 1/l6 and so on.
When optimum results are obtained fix the locking screws. To remember the position of the
azimuth, imagine that the inserted Allen key acts as a dial on the clock.
NOTE: During fine adjustment only gently fix locking screws during listening.
The adjustment screw is highly sensitive and the smallest pressure on the Allen key will alter
the azimuth and sound.
Do not attempt any adjustment when the locking mechanism is locked. Although no damage
can be done.
Significantly improved sound can be obtained by paying attention to azimuth adjustment prior
to final VTA adjustment.
